2008 Lexus IS 250 Navigation Manual - Page 241

AIR CONDITIONING (c) Rear window and outside rear view mirror defoging The system will automatically shut off when the defogger has operated about 15 minutes. If further defrosting or defogging is desired, simply actuate the switch again. When the surface has cleared, push the button once again to turn the defogger off. Continuous use may cause the battery to discharge, especially during stop-and-go driving. The defogger is not designed to dry rain water or to melt snow. If the outside rear view mirrors are heavily coated with ice, use a spray de-icer before operating the system. To turn the electric rear window and outside rear view mirror defogger on, push the button above. The "ENGINE START STOP" switch must be in IGNITION ON mode. The thin heater wires on the inside of the rear window and the heater panels in the outside rear view mirrors will quickly clear the surface. Keep your hands off the mirror faces when the system is on. The indicator light is on when the defogger is operating. NOTICE D When cleaning the inside of the rear window, be careful not to scratch or damage the heater wires or connectors. D To prevent the battery from being discharged, turn the switch off when the engine is not running. CAUTION Since the mirror surfaces can get hot, do not touch them when the system is on. 261